Head drum assembly for tape recorder and method of making same

Abstract

Disclosed is a head drum assembly of a tape recorder. An elastic body is mounted between upper and lower bearings as preloading means, in which the upper and lower bearings are interposed between a rotary drum and the shaft. As a result, the elastic body elastically biases the inner races of the upper and lower bearings upwardly and downwardly, respectively, whereby preload can be applied to each of the upper and lower bearings.

1. A head drum assembly of a tape recorder, comprising:
 a shaft; 
 a rotary drum which supports a magnetic head for recording and reproducing information by scanning a running magnetic tape, the rotary drum having an axial bore with an upper recess and lower recess; 
 a fixed drum, press-fined onto a lower part of the shaft, engaged on the axial bore of the rotary drum, parallel to the rotary drum; 
 an upper bearing having an inner race and an outer race, the outer race being press-fit into the upper recess of the axial bore of the rotary drum, the inner race being press-fit around the shaft; 
 a lower bearing having an inner race and an outer race, the outer race being press-fit into the lower recess of the axial bore of the rotary drum, the inner race being press-fit around the shaft; and 
 an elastic body mounted on the circumferential surface of the shaft between the inner races of the upper and lower bearings, the elastic body directly contacting the inner races to generate a preload force at a predetermined angle with respect to the shaft. 
 
   
   
     2. The head drum assembly of a tape recorder according to  claim 1 , wherein the elastic body comprises a coil spring. 
   
   
     3. The head drum assembly of a tape recorder according to  claim 1 , wherein the predetermined angle is approximately 30°. 
   
   
     4. A head drum assembly of a tape recorder, comprising:
 a shaft; 
 a rotary drum which supports a magnetic head for recording and reproducing information by scanning a running magnetic tape, the rotary drum having an axial bore with an upper recess and lower recess; 
 a fixed drum, press-fitted onto a lower part of the shaft, engaged on an axial bore of the rotary drum, parallel to the rotary drum; 
 an upper bearing having an inner race and an outer race, the outer race being press-fit into the upper recess of the axial bore of the rotary drum, the inner race being press-fit around the shaft; 
 a lower bearing having an inner race and an outer race, the outer race being press-fit into the lower recess of the axial bore of the rotary drum, the inner race being press-fit around the shaft; and 
 an elastic body for generating a preload force which is directed at a predetermined angle from the shaft on the inner races of the bearings. 
 
   
   
     5. The head drum assembly of a tape recorder according to  claim 4 , wherein the elastic body comprises a coil spring. 
   
   
     6. The head drum assembly of a tape recorder according to  claim 5 , wherein the preload is applied to the inner race of the lower bearing in a downward direction. 
   
   
     7. The head drum assembly of a tape recorder according to  claim 4 , wherein the predetermined angle is approximately 30°. 
   
   
     8. The head drum assembly of a tape recorder according to  claim 5 , wherein the preload is applied to the inner race of the upper bearing in an upward direction. 
   
   
     9. The head drum assembly of a tape recorder according to  claim 8 , wherein the coil spring directly contacts the inner race of the upper bearing without contacting the outer race of the upper bearing. 
   
   
     10. The head drum assembly of a tape recorder according to  claim 6 , wherein the coil spring directly contacts the inner race of the lower bearing without contacting the outer race of the lower bearing. 
   
   
     11. A head drum assembly of a tape recorder, comprising:
 a shaft; 
 a rotary drum which supports a magnetic head for recording and reproducing information by scanning a running magnetic tape, the rotary drum having an axial bore with an upper recess and lower recess; 
 a fixed drum, press-fitted onto a lower part of the shaft, engaged on an axial bore of the rotary drum, parallel to the rotary drum; 
 an upper bearing having an inner race and an outer race, the outer race being press-fit into the upper recess of the axial bore of the rotary drum, the inner race being press-fit around the shaft; 
 a lower bearing having an inner race and an outer race, the outer race being press-fit into the lower recess of the axial bore of the rotary drum, the inner race being press-fit around the shaft; and 
 means for generating a preload force which is directed at a predetermined angle from the shaft on the inner races of the bearings. 
 
   
   
     12. The head drum assembly of a tape recorder according to  claim 11 , wherein the means for generating a preload force comprises a coil spring. 
   
   
     13. The head drum assembly of a tape recorder according to  claim 12 , wherein the coil spring directly contacts the inner race of the upper bearing to generate a preload force in an upward direction. 
   
   
     14. The head drum assembly of a tape recorder according to  claim 13 , wherein the coil spring directly contacts the inner race of the lower bearing to generate a preload force in an downward direction. 
   
   
     15. The head drum assembly of a tape recorder according to  claim 14 , wherein the predetermined angle is approximately 30°.